Health of Cloned Foals Examined in New Study

Compared to other species, cloning horses is still in its infancy. Cloning is becoming increasingly popular, yet the health of these artificially-produced foals has not been assessed in detail.

"There is very little information on the health of cloned foals currently available," said Aime Johnson, DVM, Dipl. ACT, from the J.T. Vaughan Large Animal Teaching Hospital at Auburn University College of Veterinary Medicine.

To better understand the health of cloned foals, Johnson and colleagues reviewed the physical examination findings and laboratory data (blood work, etc.) from 14 foals produced at Texas A&M University's laboratory between 2004 and 2008.

The cloned foals involved in this study were all produced using a technique called "somatic cell nuclear transfer." This technique involves taking the genetic material (DNA) from a cell donated from an adult horse and transferring it into an egg cell, then placing the egg into a recipient mare's uterus.

"In total, six of the 14 foals, or 43%, were normal," relayed Johnson.

In the remaining eight foals, the following abnormalities were most commonly noted:

Neonatal maladjustment (dummy foal);

Enlarged umbilical remnant; and

Angular limb deformities of the forelimbs.

Johnson noted, "While two of these eight foals died within one week of foaling, all of the [above-described] conditions resolved in the remaining six foals with appropriate medical and surgical management."

All 12 surviving foals were healthy at the time Johnson's report was published.

The study, "Physical and clinicopathologic findings in foals derived by use of somatic cell nuclear transfer: 14 cases (2004-2008)," was published in the May 1, 2010, edition of the Journal of the American Veterinary Medical Association.

About the Author

Stacey Oke, MSc, DVM, is a practicing veterinarian and freelance medical writer and editor. She is interested in both large and small animals, as well as complementary and alternative medicine. Since 2005, she's worked as a research consultant for nutritional supplement companies, assisted physicians and veterinarians in publishing research articles and textbooks, and written for a number of educational magazines and websites.

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